8720645 has 8 divisors (see below), whose sum is σ = 10503456. Its totient is φ = 6950736.

The previous prime is 8720629. The next prime is 8720671. The reversal of 8720645 is 5460278.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8720645 - 2⁴ = 8720629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1667 + ... + 4496.

It is an arithmetic number, because the mean of its divisors is an integer number (1312932).

Almost surely, 2^8720645 is an apocalyptic number.

It is an amenable number.

8720645 is a deficient number, since it is larger than the sum of its proper divisors (1782811).

8720645 is a wasteful number, since it uses less digits than its factorization.

8720645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6451.

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 8720645 is about 2953.0738223079. The cubic root of 8720645 is about 205.8335680890.

The spelling of 8720645 in words is "eight million, seven hundred twenty thousand, six hundred forty-five".